Adjustable back rest for chairs



Nov. 13, 1928. 1,691,034

A. J. ADAMS ADJUSTABLE BACK REST FOR CHAIRS Filed July 27, 1925 fnifnm Patented Nov. 13, 1928. i

'UNITED STATES P' TENT OFFICE.

ARTHUR J. ADAMS, or BAY CITY, MICHIGAN, ASSIGNOR To WILLIAM s. meals, or ELKHART, INDIANA, TRADING AS DOMORE 01mm coMrANY.

ADJUSTABLE BACK REST IEOR CH AIRS'.

Application filed July 27, 1925. Serial No.-46,227.

This invention relates to improvements in adjustable back rests for metallic chairs and consists of thematters hereinafter de scribed andmore particularly pointedout in the appended claims. 7 r

The primary object of the invention is to provide'an improved backrest which includes side arms, a back rest member and" brace arms rigidly secured to the side arms thus providing 'a unitary structure capable of being readily adjustable forwardly or rearwardly with respect to the seat member of the chair. I

These objects of the invention, as well as others together with the many advantages thereof will more fully appear as I'proceed with my specification.

In the drawings:

Fig. 1 is a view in side elevation of a metallic swivelling seat chair embodying my improved adjustable back rest.

Fig. 2 is a. fragmentary view in front elevation of a chair embodying my improved adjustable back rest.

Fig. 3 is a vertical sectional view as taken on the line 33 of Fig. 1.

Fig. 4 is a view in elevation on an enlarged I scale of one of the side arms of the back rest frame together with its fixed brace.

Referring now in detail to that embodiment of the invention illustrated in the aceompanying drawing ;1 indicates as a whole. a seat frame having a seat member, 2., mounted thereon in any suitable manner. Said seat frame which is rectangular in plan comprises angle bar side members Shaving vertical flanges 4 and front and rear, vertically edgewise arranged frame members legs '8. As the structure of the post and standard forms no particular part of the present invention it is not thought necessary to describe the same in greater detail.

9 indicates as a whole my improved back of strip material and is reverse'ly curved in the plane of its edges. The top portion of a said brace member is engaged against the,

outer surface of an associated arm at a point slightly below its offset top end and takes the form of that portion of the arm and is rigidlysecured thereto'as bythe rivets 16,

he bottom end of said brace member which extends into the horizontal plane of the bottom end of said. arm, is spaced a suitable distance rearwardly thereof and is provided with a hole 17. The spacing between the holes 11 and'l. respectively in the bottom ends of the arm 10 and brace 15 isequal to the spacing between the frontmost. or any other of the corresponding holes 4 and 4 in the flange 4 of the angle bar side member. When the holes 11 and 17 of said side arms and braces are aligned with say .thefrontmost holes4-4t said arms and braces may be removably fixed in this position by means of bolts 19-19. Should such an adjustmen't bring the back rest member too far forward with respect to the seat member for the comfort of the occupant of the chair, the bolts 19 are removed and the seat frame as whole moved rearwardly to bring the holes in said arms and brace into registration with the proper holes i e? in the side member of the seat frame and then secure d in this. position by replacing the bolts 19. i

It is to be noticed that the side arms are connected to the forward portion of the seat frame and the brace members to the rearward portion thereof. This construction is advantageous because it permits the said arms to be of such form as will present no appreciable interference at the sides of the seat frame to the body of the occupant and the bracebars are put under a compression strain instead of an expansion strain as heretofore. Thus the brace member may be made shorter at a saving of material and Weight Without sacrificing strength and rigidity. Being relatively short and being fixed as they are to the side arms, they do not yield to bending strains, hence always maintain their desired shape.

Again the brace members are secured directly to the side arms and the back rest member is also fixed to said arms, thus providing a unitary back rest structure Which may be easily applied to the seat frame by the purchaser and readily adjusted for his or her best comfort.

While in describing my invention, I have referred to certain details of mechanical construction as well as arrangement and form of parts thereof, I do not Wish to be'limited thereto except as may be pointed in the appended claim.

I claim as my invention:

A chair embodying therein a seat frame including side members having front and rear sets of holes therein, a back rest frame comprising a backrest, side arms fixedly secured to the back rest and brace bars rigidly fixed to said side arms at points between the endsthereof, the bottom ends of the side arms and the brace bars being disposed in the same horizontal plane and fixed relative to each other, the bottom end of each side arm and brace bar being provided with open ings adapted to register respectively with predetermined holes of said front and rear sets of holes in the side members of said seat frame and means passing through said registering holes to secure said back rest frame in the desired forward or rearward adjusted position on said seat frame With- ,out changing the angularity of the back rest or the side arms relative to each other. In testimony Whereof,I have hereunto set my hand, this 6th day of July, 1925,

ARTHUR J. ADAMS. 

